Fluid pump



May 17, 1960 J..|1SHER 2,936,713

FLUID PUMP Filed Dec. 14, 1955 3 Sheets-Sheet l d, INVENTOR. 2 il JOHN C. FISHER ATTO R N EYS J. C. FISHER May 17, 1960 FLUID PUMP 3 Sheets-Sheet 2 Filed Dec. 14, 1955 INVENTOR. JOHN C. FISHER ATTO RN EYS May 17, 1960 J. c. FISHER 2,936,713

FLUID PUMP Filed Dep. 14, 1955 3 Sheets-Sheet 5 VT@ vCK W 24 l YIIIIA INVENTOR. JOHN C. FISHER BY J l /l/ 'c/Y ATTORNEYS nited States materit ice This invention relates to an improved pump particularly suitable for use in transmitting corrosive liquids, solvents and other uds which cannot be satisfactorily han dled by conventional pumps r Displacement, rotary and centrifugal type pumps not only embody one or more impellers and other moving parts with which the liquid being pumped comes in contact, but also a power-transmitting element driven from an external source. When such pumps are used to transmit corrosive liquids, solvents, etc. the moving parts and other surfaces coming inv contact with the liquid must either be made from a relatively costly, corrosive-resistant material, or they must be provided with a protective coating which'after a relatively short period of use is apt to wear or become stripped, thus introducing contamination into Ythe liquid being pumped. Moreover, since such pumps are driven from an external source it is necessary to use a packing gland or the like seal which must be periodically replaced in order to guard against leakage. Consequently both the initial and maintenance costs of such pumps are relatively high.

Pumps' of the type embodying an oscillating chamber having at opposite ends inlet and outlet ports provided with one or more check valves, such as shown in U.S. Patents 315,171 dated April 7, 1885, 991,708 dated May 9,1911, and'2,354,188 dated July 25,v 1944, have not achieved any degree of success, due mainly to low efciency, excessive vibration and general unreliability. Hence, this type of pump was long ago abandoned in favor ofthe aforementioned conventional types.

The principal objects of the present invention are to overcome the aforementioned difculties and provide a pump of the oscillating chamber type which is etlicient and reliable in operation and which may be made from relatively inexpensive commercially available materials.

lMorespecitic objects are to provide a pump capable of handling a uid containing solid or abrasive particles, such as encountered in a coolant system for machine tools, to provide a pump which can safely handle toxic materials such las radio-active substances and highly inammable or explosive fluids, etc., where leakage must be avoided, and to provide a pump the output of which may be varied without using a valve or the like. Y

.Further objects relate to features of construction and will be apparent from a consideration of the following description andthe accompanying drawings, wherein:

Fig. 51 -is an end view of a linear oscillating pump constructed in accordance with the present invention;

iS a

Fig. l;" 4

Fig. 3 is a section on the line 3 3 of Fig. 2;

Fig. 4 is a section on the line 4-4 of Fig. 1',

Fig. 5`is'an axial section through a rotary oscillating pump constructed in accordance with the present invention;

Fig. 6 is a section on the line 6-6 of Fig. 5;

" Fig. 7 is a section on the line 7-7 of Fig. 5;

section' substantially on the line 2-2 of.

936,713 .efenfed .May 17, 1.960

Fig. 8 is a schematic view of a modified `form of linear oscillating pump;

Fig. 9 is a View similar to Fig. 8 but showing an alternative arrangement interconnecting the discharge and intake ports; and

-Fig. 10 is a detail showing another form of hydraulic rectifier.

In accordance with the present invention I provide a uid pump comprising aplurality of enclosures or accelerator tubes having relatively rigid walls i.e., walls made of a material which is capable of sustaining static stresses without undergoing appreciable distortion when subjected to the operating pressure for which the pump is designed. Each enclosure or accelerator tube is supported for oscillatory movement, which may be either Y rectilinear or rotary, and is provided with spaced ports preferably arranged at or adjacent to points where the alternating pressure dilterence has a maximum value.

Conduits having relatively flexible sections interconnect the respective ports so that the pressure gradients are additive, these conduits constituting an internal circuit which includes the enclosures and flexible sections, and at least a part of an external circuit through which it is desired to transmit a uid. Associated with the internal circuit are one or more fluid rectiers, each of which may consist of a check valve, an unsymmetric orice or Venturi, a static Venturi with a port in its throat, or the like device which requires'a greater loss of fluid energy for a flow in one direction than in the other. In any case the uid rectiers are operative to oppose fluid flow in one direction at least through the external circuit and inA some cases through both the internal and external circuits. Accordingly, such rectiiiers may be applied to one the conduits. In any case, the particular material selected' .will depend on the type of uid on which the pump is to operate. These same considerations are applicable to the external circuit and parts associated therewith.Y

Any suitable means may be employed to oscillate the enclosures simultaneously in opposite and/ or symmetrically disposed directions so as to impart the desired accelerations to the fluid therein. Although the frequency may have any value throughout a wide range, as a practical matter the operating frequency should not be less than 20 cycles per second, and the maximum operating frequency need not exceed cycles per second. To this end one or more electrodynamic vibrators or the like may be used, or the mechanical equivalent such as a crank,

cam, or other type of reciprocating motor. The preferred form of vibrator is the electrodynamic type wherein a direct current magnetic eld acts on one or more coils carrying an alternating current, slnce 1n this type of device the frequency and acceleration may be closely con trolled by varying the frequency and amplitude of the alternating current.

The flow induced in the internal circuit in response to oscillations of the enclosures is either a purely alternating ow, or a combination of an alternating and direct flow, comparable to a pulsating or rectified alternating current, and it depends upon the number and arrangement of oscrllating enclosures that make up the pump. The flow in the external circuit is primarily unidirectional and maya be pulsating to a greater or lesser extent. In order to insure a more even pressure and fiow in the external circuit the discharge line may include an air dome or pressure-loaded piston or diaphragm operative to maintain a predetermined pressure on the fluid in the external circuit, thereby eliminating or minimizing the waterharnmer or pressure surges. Y

Since the pressure differential of each enclosure varies as the product of the fluid mass'density within the enclosure, the height or length of the enclosure in the direction of acceleration and the acceleration of the fiuid (mha), the enclosure is preferably as long as feasible in the direction of acceleration in order to insure operating efficiency. Accordingly, a continuous length of tubing may be so wound or arranged on a suitable support or carrier as to define two or more groups of enclosures which are oscillated klinearly in opposite directions; or a continuous length of tubing may be wound to define cooperating helices supported for rotary oscillation in opposite directions; or a group of tubes may be connectedl at their opposite ends by headers and supported so as to cooperate with a similarly constructed group which oscillate linearly in the opposite direction, the respective headers being provided with ports which are connected with the conduits having flexible sections.

Where the enclosures are designed to oscillate rectilinearly, it is desirable if not necessary in order to insure a smooth and eflicient operation that the oscillations of one group either be in a .direction opposite that of the companion group having the same mass, or the several groups should oscillate in such timed relation with respect to each other that their masses are dynamically balanced; and the same considerations are generally applicable to enclosures designed for rotary oscillation.

j A further feature contributing greatly to efiiciency and smooth operation in both rectilinear and rotary oscillation enclosures is the provision of balanced springs exerting opposing forces or torques and effective to hold the enclosures in center or neutral position when at rest. With a rectilinear oscillating enclosure a pair of opposed compression springs is preferably employed, the combined stiffness of the springs being such that the natural frequency of oscillation of the mass (enclosure and parts oscillating therewith) is equal to the frequency o-f the vibrator or oscillation-imparting device. With a rotary oscillation enclosure a pair of balanced opposed spiral springs is preferably employed to act on the enclosure so as not only to hold it in a center or neutral position when at rest, but also to produce a condition of mechanical resonance at the frequency of the vibrator. In both cases the driving force applied to the oscillating enclosure by the vibrator is used only to overcome the bearing friction and the opposition of the fluid to flow through the fluid circuit.

Referring to Figs. l to 4, the embodiments shown therein illustrates a pump designed for linear oscillation and comprises a main pump section 1, a rectifier section 2, and an clectrodynamic vibrator 4 which operates the pump. The section 1 comprises a cylindrical housing 5 one end of which is secured to a circular retainerv plate 6 and the other end of which is secured to an annular pole plate 8 of the 'vibrator 4. One end of a central guide rod 1t) has a threaded connection with a cylindrical projection 11 integral with the yoke or core 12 of the vibrator and the other end of this rod is anchored to the center of the retainer plate 6 by a nut 14. Four circumferentially spaced guide rods 15 are secured to the marginal portions of the pole plate 8 and retainer plate 6 and these guide rods not only serve firmly to clamp the housing in position, but also to provide guides for slidably supporting the enclosures or accelerator tubes hereinafter described.

Adjacent to the opposite ends of the central guide rod 10 are slidable bushings 16 and 18 supporting a tube on which is mounted an inner cage comprising anfined by the pole plate 8 and a central extension 11. The

outer end of the tube 30 carries an armature coil 34 which causes the inner cage assembly to oscillate on the guide rod 1f) in response to the passage of alternating current therethrough.

Adjacent to the opposite ends of each of the outer guide rods 15 are slidable bushings 35 and 36 supporting tubes 38 on which the outer cage is mounted. The outer cage comprises annular end plates 40 and 41 each formed with circumferential grooves 44 and 45 and three intermediate annular supporting members 46 formed with six aligned circumferentially spaced openings 48. Fitting the inner periphery of the end plate 41 and telescoping with the shell or tube 30 is one end of a second shell or tube 50, the outer end of which projects into the gap 32. The outer endof the tube 50 carries an armature coil 52 wihch may either be so wound or connected with the coil 34 as to oscillate simultaneously in the opposite direction in response to the passage of an alternating current through the coils.

Inwardly of the pole plate 8 is an annular recess 55 which receives a field coil 56 and several wedge pads 58 are inserted between the field coil and the adjacent walls of the core and pole plate, these parts being firmly held in position by cap screws 60 which are threaded into the pole plate 8. The field coil 56 may be connected with any suitable source of direct current so as to pro duce a high linx concentration across the annular gap 32. The pump consists of a single length of suitable tubing 62 such as nylon, a halogenated poiyethylene suchv -as Tefion, polyvinylidene chloride such as Saran, all ofl which are relatively fiexible and possess a high fatigue resistance and are yet sufficiently strong or rigid to withstand high pressures without undergoing appreciable dis-v tortion. The tube 62 passes through openings 64 and 65 in the retainer plate 6 and clearance slots in the end plates 21 and 40, and is wound toroidally Athrough the openings 28 and 48 of the inner and outer cages, as

shown in Figs. 2 and 3, so as to provide lsix inner convolutions or accelerator tubes 66 supported by the members 26 and siX outer convolutions or accelerator tubes' 68 supported by the members 46.

The outer end of a coil compression spring 70 is seated in a circumferential groove formed in the extension 11 and its inner end is received in the groove 25 so as to urge the inner cage inwardly and one end of a corresponding coil spring 72 is seated in a groove on the inner face of the retainer plate 6 with its outer end in the groove 24 to oppose the action of the spring 70. A coil compression spring 74 seated in the groove 45 of the end plate 41 acts against the pole plate 8 to urge the outer cage inwardly and an opposing spring 75 seated in the groove 44 of the end plate 40 acts against the retainer plate 6. The springs 70, 72 and 74, 75 not only normally hold the inner and outer cages in a central or neutral position when the parts are at rest, but they are selected so that theirstiffness and characteristics produce a natural frequency of oscillation of the mass of both cage assemblies which is at least approximately the same as the.

which-receives 'a fullrwave 'fluid rectifier 80. This particular rectifier comprises a cylindrical block or body 82' having four longitudinally extending venturi-like passages 83, 84, 85 and 86. The inner ends of the passages 83 and 85 are connected by a passage 87 and the inner ends of the passages 84 and 86 are connected by a passage 88. The outer ends of passages83 and 84` are connected by a passage 90 and the outer ends of passages 85 and 86 are likewise connected by a passage 91. The passages- 83 and 84 are providedwith ballchecks 93 and 94 each provided with a retainer pin,tl1e arrangement being such that .inward flow from the passage 90 is prevented, but outward flow to the passage 90 isr permitted. The passages 85 and 86 are alsoprovided with ball checks 95 and 9 6 and associated retainerlpins the arrangement being such that inward `floviI from-the passage 91 is permitted, but-outward flow to the passage 91 is prevented. The ends ofthe tubing 62 are connected with passages 87 and 88,y the lslack of the -tubing being sufficient to prevent interference-with the oscillations of the inner and outer cage assemblies.

neously there will be a reverse surge created by the oscil lation of thecuter convolution 68 in the opposite direc-u tionvwhich draws fluid in through passage 85; when oscil'` lations ofthe inner and outer convolutions are reversed a pressure surge transmitted from the outer convolution 68 to the passage 87 forces fluid outwardly through passage 83 and simultaneously the reverse surge in vthe con# volution 6 6 draws fluid inwardly through passage 86,

thus producing a full waverectification.

In operation the pump is first primed so that there is a continuousbody of fluid from the intake to the discharge, and the field coil 56` may Athen b e connected with a suitable source of direct current. Thelines connecting the armaturecoils 34 and 52 are then connected with a source of alternating current of the desired frequency, whereupon the inner and outer cage assemblies are oscillateld invv opposite directions at the same-frequency as the alternatingcur'rent. By varying the yfrequency and amplitude ofthe alternating current, the frequency of oscillation of the cage assemblies and the'acceleration imparted to the fluid therein may be varied correspondingly. If, for example, a 60 cycle frequency is used both the inner and outer cage assemblies oscillate 60 times, per second in opposite directions, and due to the acceleration imparted to the fluid there will be 120 pressurel surges per second forcing fluid out through the discharge and the same number fof surges drawing fluid in through the intake.

Hence, fluid alternatingly surges into the inlet passages 85and 86 simultaneously with fluid alternatingly surging outwardly through outlet passages 83 and 84. Since the volumeof fluid transmitted, in response to each surge is relatively small, being less .than the volume of the inlet` and connecting passages, the path of flow is from the intake 99, inlet passages 85, 86, along the connecting passages 87, 88, outwardly-through the outlet passages 83 and 84 tothe discharge 98, there being little or no fluid circulating through the inner and outer convolutions 66, 68,7..V vIjIoweyer, it is to be understood that,v if desired a rectifier of different Ydesign couldbe employed -so as to secure a pulsating, unidirectional flow through the entire SystemiY 3. The embodiment-shown in Figs. -to 7 isbasically the same as that of ligsl to: 4,*but is designed for angular acceleration or rotary oscillation.' This embodiment comprises -atnain pump section ll, a lrectifying section 102 The passage 90 is -connected with a discharge outlet 98 and the passage 91A is connected with an intake 99, it being understood that the1intake and discharge may be appropriately` connected with an exterior4 and a vibrator section 104. The pump section comprises a cylindrical casing 105, one end of which adjoins a retain- One end of the supporting shaft is threaded intog the cent of the pole piece 112 of theqvibrator and the other end projects through an opening in the retainer plate to receive a clamping nut 114 which firmly holds the retaining plate, casing and pole piece in position. Mounted adjacent to theopposite ends of the shaft 1 10 are bushings 115 and 116 which rotatably support an inner torque tube 118, and spaced bushings and 1 21 rotatably support an outertorque tube 122. A flanged driving disk 124 having an elongate hub portion 125 is fixed to the inner torque tube 1,18 and a flanged driving wheel 128 having an elongate hub 130 is fixed to the outerI torque tube 122, there being anti-friction washers `132 interposed between the hubs of the driving disk and wheel to minimize friction between the contiguous parts.

The flanged periphery of the driving wheel 128 supports an inner pump barrel 135 having helical grooves 136 formed in its outer face.` A second flanged driving wheel .138 having an elongate hub 139 is mounted on a tapered spindle bushing 140 which rhas a press fit within the inner torque tube, the huhof the driving wheel 138 having a presswfit about the bushing 140 due to a re-y tainer nut 142,. Anti-friction washers 144 and 145 are,

provided to minimize friction and insure a smooth operation. The flanged periphery of the driving wheel 138 supports an outer pump barrel 148 which is also formedwith helical groovesV 150 on its outer face.

With the construction and arrangement thus far described both pump barrels 135 and 148 are independently rotatable about the same axis, the inner barrel being supported by the outer torque tube 122 and the outer barrel being drivenand -supported by the inner torque tube 118. The accelerator tubes supported by the barrelsl 135 and 148 consist of a single length of tubing 155 made from any of the materials above mentioned. The tubing 144 extends from the rectifier section through an opening 156 in the retainer plate, then helically about the outer barrel 148 to provide the outer accelerator tubes or chambers 158, inwardly through an appropriate opening ini the outer barrel and then helically about the inner barrel 135to provide the inneraccelerator tubes or chambers 160, and finally back through opening 156 to the rectifierl section 102, it being understood that the coils arere,

tained in the grooves 136 and 150 by an adhesive or other suitable means and that in passing to and from the bar- 5 rels sufficient slack is provided to permit the two assem-v blies to oscillate simultaneously in opposite directions through an angle of the order of 15 without interference from one another.

Rotary oscillatory movement or angular acceleration is provided by an electrodynamic vibrator comprising the pole piece 112 which carries upper and lower field coils and 1 71. The pole piece 112 is surrounded by the magnetic ring member 108 which is held in position by supporting shells 172, 173 and cap screws 174. Thev inner periphery of the ring 108 together with the ends'v of the pole piece 112 dene a pair of arcuate gaps 1.75

and 176 of high flux concentration when the direct cur-.g

rent is passed through these coils.

A cylindrical inner shell or tube 180 has, a pressy fitabout the flanged periphery of the driving disk 124 and this shell projects into the gaps and 176, the oppo site surface portions of the shell carrying spirally wound.,

armature coils 182 and l183. vLikewise an outer shell rotates or oscillates the shells simultaneously in opposite directions when a direct current is passing through the field coils 170 and 171, the frequency of such oscillations andv angular movement of the barrels and associated parts being governed by thev frequency and amplitude of the alternating current.

In order to maintain constant the average, or rest, po-

sition of each pump-and-armature assembly, four spiral torsion springs are employed, two for the outer assembly and twofor the inner assembly. Referring to the rectifier end of the pump, Vtheouter ends'of spiral springs 190 and 191 are rigidly secured' to a fixed stud 192 carried by the retainer plate 106 and the inner ends of these springs are rigidly secured to a movable stud 194 carried by driving wheel 138. The spring 190 exerts a counterclockwise torque on wheel 138 when viewed from the rectifier end o f the pump and spring 191 exerts a clockwise torque on the wheel 138 when viewed from the same end.

Referring tothe vibrator end of the pump, the outer ends of a pair of spiral springs 195 and 196 are rigidly secured to a movable stud 197 which passes through an arcuate opening 198 in the driving disk 124 into the periphery of driving wheel 128, and the inner ends of these springs are rigidly secured to a fixed stud 200 carried by a radial lug 201 integral with a collar 202 that is fixed to shaft 110. Here again the springs 195 and 1,96 exert opposite torques on the driving wheel 128. The collar 202 and retainer plate 106 cooperate to provide thrust surfaces which prevent axial movement of the inner and outer pump assemblies without interfering with their rotary movements.

The torques of these springs will at some angular position ofthe driving wheels 124 and 138 be equal and opposite, and the associated structure will then assume a fixed angular position if no current flows in the armature coils, this rest position being precisely that at which the torques of the springs are equal and opposite. A second function of each pair of spiral springs is to produce a condition of mechanical resonance in the angular oscillation of each assembly at the frequency of the alternating current in the armature coils. In this way, the entire torque produced by each armature coil is used only to overcome the bearing friction and opposition of the fluid to flow through the fluid circuit. Hence, none of the torque is wasted in accelerating the dead mass of the-oscillating structures.

The fluid rectifier assembly in section 102 is identical to that shown in the embodiment of Figs. l to 4 and since the same reference characters are applied to like parts a further description is unnecessary. In all material particulars the mode of operation is substantially identical, except that in the first embodiment there is a rectilinear acceleration of the fluid, while in the latter embodiment there is an angular acceleration tangentially to the helical coils.

An outstanding feature of both electrodynamic vibrators is that the magnetic fields produced by the armature coils are equal and opposite and hence a high power factor is maintained without introducing capacitance. Moreover, the use of a single field for both armatures not only doubles the mechanical output obtainable with a given field structure, but since the coils and the associated assemblies simultaneously oscillare in opposite directions, the opposite reaction on the field coil structure that would otherwise be encountered is effectively eliminated.

Another feature of the embodiments of Figs. lto 7 is that both may be advantageously used to pump gases which otherwise could not be feasibly handled and to this end the accelerator tubes are filled with a low vapor pressure liquid or propellant fluid that is chemically inert to the gas to be pumped, it being understood that with a full wave rectifier 80, there is no travel of the fluid through the accelerator tubes.

corresponding parts. In this type of rectifier the tapering passages 83a and 84a communicate with passages 87a and- 88a through an opening which flares outwardly so as to produce a great turbulence and consequent resistance toj flow from 83a to 87a, etc. Although such a rectifier is not as'positively operating as a ball, swing or plug check valve, yet it is quite effective where a slight back flow is' either desirable or permissible, the main advantage beingthat no moving parts are involved.

Various other types of fluid rectifiers may bc employed in conjunction with oscillating enclosures designedY to produce a pulsating unidirectional flow induced either mechanically or electrodynamically, and two such sys-- tems are schematically shown in Figs. 8 and 9. In the embodiment of Fig. 8 three radially disposed, circumferentially spaced holders 210, 211 and 212 are supported about a common axis in guideways 214, 215 and 216,`

each of these holders carrying a plurality of accelerator tubes or enclosures connected at opposite ends by headers or other suitable means. Cranks and connecting rods 218, 219 and 220 are fixed to a common drive shaft 222 which may be driven by a variable speed motor (not shown). The headers at the inner ends of the accelerator tubes are connected by flexible conduits 224, 225 and 226 to a common return line 228, and the headers at the outer ends of the tubes are connected with flexible conduits 230, 231 and 232 which include check valves or rectiliers 234, 235 and 236, respectively. The con-` duits 230, 231 and 232 are connected on the downstream side of the rectifiers to a common discharge line 238 lead-l ing to the inlet of a receiver 240 containing a fluid to bevl circulated, such as a cooling system, the outlet of whichis connected to return line 228. The three groups of accelerator tubes are spaced about the drive shaft 222 and since their respective assemblies have the same mass, they are dynamically balanced while being oscil' lated. l

In operation, the oscillations of the assemblies induce a pulsating flow, comparable to that of a three-phase electric circuit, through discharge lines 230, 231 and 232, and the rectifiers in these lines prevent a reverse flow therethrough. Hence, the flow into the receiver 240 is The system shown schematically in Fig. 9 is generally similar to that shown in Fig. 8 and the same or similar reference characters are applied to corresponding parts,`

it being understood that the particular type or design of accelerator tubes is not of primary importance. ner ends of the assemblies of holders 21011, 21.11 and 212a are connected together by flexible conduits 224e, 225e and 2265i, and the outer ends are connected by conduits 23651, 231e: and 232a to a rectifying system which includes branched circuits 241, 242 and 243. Each branch iticludes a check valve opposed to the check valve in the companion branch, and the corresponding check valves 244, 245 and 246 are connected with a common dis` charge line 24S leading to the receiver 250. Likewise the ycommon return line 252 is connected with the check valves 254, 255 and 256 which prevent reverse ow inV the line 252.

In operation the oscillations imparted to the accelera` asser-1e' tor tubes or enclosures produce an alternating flow inthe conduits 230e, 231a ,and 232a' and also the lines 224e, 22541 and 226e, but the rectiers'244, 245 and 246 associated with the branched lines 241, 242 and 243 permit only a unidirectional, pulsatingow in the discharge line 248. The rectifiers associatedfw'ith the return line 252 likewise prevent a reverse flow in this line and hence there is a unidirectional pulsating flow in the return line 252. As a result the main body ofuid being circulated does not flow into the internal circuit including the accelerator tubes, as in the embodiment of Fig. 8, but rather is circulated through the rectifying system, then to the receiver 250 and back to the rectifying system, as in the embodiments of Figs. 1 to 7.

It will be noted that in each of the embodiments herein shown the entire pumping apparatus including the lluid rectifiers provides a completely enclosed system which may be made from a suitable material inert to the fluidv It is to'be understood that this disclosure'is for the purpose of illustration and that various modifications `and changes may be made such, for example,'as the substitution of the particular pumps of the embodiments of Figs. l lto 7, forthose ofthe embodiments of Figs. Sand 9, and the use of armatnre'ircuits' .connected to a three-phase power source, andvthat all such changes and modifications may be made without departing from the spirit and scope of the invention as set forth in the appended claims. L

I claim: o o

1.l A fluid pump vcomprising a plurality of enclosures having radially non-expansible walls, each enclosure having spaced ports, conduits having relative flexible sections interconnecting said ports so as to define an internal circuit which includes said enclosures and llexible sections wherein the' pressuregradient is additive and an 'externalcircui uid rectifiers interposed between the internal'and external' circuits so as to oppose fluid flow flexible sections wherein the pressure gradient is additive` and an external circuit, lluid rectifiersv interposed between the internal and external circuits so as to oppose fluid ilow in one direction through the external circuit, and means for vsimultaneously oscillating said enclosures at a selected uniformfrequency linr opposite directions in a rectilinear,v -pathso as to .induce a unidirectional flow through' said external circuit. v l

3.'A`,'iluid pump comprising a plurality of tubular enclosures having radially non-expansible walls and arranged in elongate juxtaposed coils, each enclosure having spaced ports, conduits having relatively flexible.. sections interconnecting said ports so.` as to define an internal circuit which includes said enclosures and'llexiblesections whereu inltliepressure .gradient isad-ditive and', an external circlit,`il`u`id rectifiers -interposed between the internal and external circuits so as to oppose fluid flow in one direction through said external circuit, and means for simultaneously oscillating said coils at a selected uniform frequency mounted telescopically disposed annular enclosuresfhavin opposite directions so as' to induce a unidirectional flow through said external circuit.

4. A fluid pump comprising a plurality of annular enclosures having lradially non-expansible walls, each en-l closure having spaced ports, conduits having relativelyV flexible sections interconnecting said ports so as to de-1 line aninternal circuit which includes said enclosures: and flexible sections wherein the pressure gradient is additive and an external circuit, uid rectifiers interposed between theinternal and external circuits so as to op-v pose fluid 4flow in one direction through said external circuit, and means for simultaneously imparting a rotary oscillatory motion to said enclosures at a selected uniform frequency so as to induce aunidirectional tlow through said external circuit.

5. A lluid pump comprising a plurality of coaxially mounted annular enclosures having radially nonexpansi ble walls, each enclosure having spaced ports, conduits having relatively flexible sections interconnecting saidl ports so as to define an internal circuit which includes said enclosures and flexible sections wherein the pressure gradient is additive and an external circuit, lluid rectifiers interposed between the internal and external circuits so as to oppose fluid flow in one direction through said external circuit, and means for simultaneously imparting opposite rotary oscillatory motion to said enclosures at a selected uniform frequency so as to induce a unidi` rectional flow through said external circuit.

6. A fluid pump comprising a plurality of coaxially ing vradially non-expansible walls, each enclosure'having spaced ports, conduits having relatively flexible `sections interconnecting said ports so as to define an internal cir. cuit which includes said enclosuresv and flexible sections wherein the pressure gradient is additive and an external circuit, lluid rectifiers interposed between the internal and external circuits so as to oppose lluid llow in one direction through said external circuit, and means for simultaneously imparting opposite rotary oscillatory motion to said enclosures at a selected uniform frequency so as to induce a unidirectional flow through said external circuit.

7. A fluid pump comprising a plurality of spaced .enclosures having radially non-expansible walls, said enclosures being slidably mounted to oscillate in fixed paths and having masses that are dynamically balanced when oscillating, each enclosure having spaced ports, conduitsv entially spaced, radially disposed enclosures having radially non-expansible walls, each enclosure being slid' ably mounted to oscillate radially of a common center, the masses of said enclosures being dynamically balanced when oscillating, each enclosure .having spaced ports, conduits having relatively flexible sections interconnecting said ports so as to define an internal circuit which includes said enclosures and flexible sections whereinv the pressure-gradient is addi-tive and an external circuit, fluid rectiiiers interposed between ythe internal and ex, ternal circuits so as to oppose lluid flow in one direc! tion through said yexternal circuit, and means a-t said c ornrnonV center for s imultaneously oscillating said enclosures at a selected uniform frequency and in timed relation so as to induce a unidirectional flow through said, external circuit.

dially non-expansive wallsv and spaced ports, conduits having relatively flexible sections connected with said ports to provide a discharge outlet and an inlet, a fluid rectifier connected to the discharge outlet so as to oppose fluid flow inwardly through the discharge outlet, means operating at a predetermined frequency for oscillating said enclosure so as to induce an outward fluid flow through said discharge outlet, and balanced springs acting on said enclosure so as to oppose oscillatory movement thereof, the force exerted by said springs being such that the natural frequency of said enclosure is at least approximately equal to the predetermined frequency of the oscillating means.

l0. A fluid pump comprising an elongate enclosure having radially non-expansible walls and spaced ports, conduits having relatively flexible sections connected with said ports to provide a discharge outlet and an inlet, va fluid rectifier connected to the discharge outlet so as to oppose fluid flow inwardly through the discharge outlet', means operating at a predetermined frequency for oscillating said enclosure in a rectilinear path so as to induce an outward fluid flow through said discharge outlet, and balanced helical springs acting on said enclosure so as to oppose oscillatory movement thereof, the force exerted by said springs being such that the natural frequency of saidenclosure is at least approximately equal lo the predetermined frequency of the oscillating means. ll. A fluid pump comprising an annular enclosure having radially non-expansible walls and spaced ports, conduits having relatively flexible sections connected with said ports to provide a discharge outlet and an inlet, a luid rectifier connected to the discharge outlet so as to oppose fluid flow inwardly through the discharge outlet, means operating at a predetermined frequency for oscillating said enclosure in a rotary path so as to induce an outward fluid flow through said discharge outlet, and balanced spiral springs acting on said enclosure so as to oppose oscillatory movement thereof, the force exerted by said springs being such that the natural frequency of said enclosure is at least approximately equal to the predetermined frequency of the oscillating means.

l2. A fluid pump as set forth in claim l, wherein the oscillating means operate at a predetermined frequency, and 'balanced springs act on said enclosures so as to oppose oscillatory movement, the force of said springs being such that the natural frequencies of the oscillating enclosures .is at least approximately equal to that of said oscillating means. i

13. A fluid pump as set forth in claim 2, wherein the oscillating means operate at a predetermined frequency, and balanced helical springs act on said enclosures so as to oppose oscillatory movement, the force of said springs being such that the natural frequencies of the oscillating enclosures is at least approximately equal to that of said oscillating means.

14. A fluid pump as set forth in claim 4, wherein the oscillating means operate at a predetermined frequency, and balanced spiral springs act on said enclosures so as to oppose oscillatory movement, the force of said springs being such that ythe natural frequencies of the oscillating enclosures is at least approximately equal to that of said oscillating means.

15. A fluid pump as set forth in claim 2, wherein a plurality of fixed parallel guide rods slidablysupport said enclosures for rectilinear oscillation.

16. A fluid pump as set forth in claim 6, wherein a plurality of coaxial telescopically disposed shafts rotatably support said enclosures for rotary oscillation.

l7. A fluid pump comprising an elongate enclosure having a radially -non-expansible wall, a flexible section l2 having a radially non-expansible wall connected with one end portion of said enclosure, a propellant fluid in said enclosure and flexible section, means for oscillating said enclosure at a frequency of at least 20 cycles per second so as to produce an alternating fluid flow therein, and a fluid rectifier having an intake port, a discharge port,

means between the discharge and intake ports for oppos-A ing fluid flow outwardly through said intake port and inwardly through said discharge port, and a third duct between said means connected with said flexible section so that a unidirectional fluid flow through said discharge port takes place in response to alternating fluid flow inA said enclosure and flexible section.

18. A fluid pump comprising an elongate enclosure having a radially non-expansible wall, flexible sections each having a radially non-expansible wall connected with the end portions of said enclosure, a propellant fluid in said enclosure and flexible sections, means for oscillating said enclosure at frequencies of at least 20 cycles per second so as to produce an alternating fluid flow therein, and a fluid rectifier having an intake port, a discharge port,v

means between the discharge and intake ports for opposing fluid flow outwardly through said intake port and inwardly through said discharge port and conduits con-A necting said flexible sections with said rectifier between said means so that a unidirectional fluid flow through said discharge port takes place in response to alternating fluid flow in said enclosure and flexible sections.

19. A fluid pump comprising an elongate enclosure having a radially non-expansible'wall, a flexible section having a radially non-expansible wall connected with one end portion of said enclosure, a propellent fluid in saidy enclosure and Vflexible section, means for oscillating said.A enclosure at frequencies of at least 2O cycles per second so as to produce an alternating fluid flow therein, and a fluid rectifier having an intake port, a discharge port,

check valves for opposing fluid flow outwardly through said intake port and inwardly through said discharge port and an inlet between said valves connected with said flexible section so that a unidirectional fluid flow through said discharge port takes place in response to alternating fluid flow in said enclosure and flexible section.

20. A fluid pump comprising an elongate enclosure having a radially non-expansible wall, flexible sectionsl each having a radially non-expansible wall connected with the end portions of said enclosure, a propellant fluid in said enclosure and flexible sections, means for oscillat- Y ing said enclosure at frequencies of at least 20 cycles per second so as to produce an alternating fluid flow therein, and a fluid rectifier having an intake port, a discharge port, check valves for opposing fluid flow outwardly through said intake port and inwardly through `said discharge port and inlets between said valves connected with said flexible sections so that a unidirectional fluid flow through said discharge port takes place in response to alternating fluid flow in said enclosure and flexible section.

References Cited iin the file of this patent 

